Red nuggets: environments of the most massive ultra-compact galaxies at 0.5<z<0.9

Red nuggets, massive ultra-compact red galaxies, are already scarce at redshift z>2, but at lower redshift become even rarer. Recently, different works contributed to the census of relics at z < 0.5, gathering less than 100 candidates, leaving the intermediate redshift still unexplored. The pioneering sample of red nuggets at intermediate redshift discovered with the VIPERS survey (Lisiecki et al., submitted) provides the next step to understanding the evolution of massive galaxies.
Counterintuitively, simulations predict that the low-z red nuggets should reside in galaxy clusters, where merging events predominate. From the observational point of view, the overall picture is far from clear. Some observations support the simulation view of finding red nuggets in galaxy clusters with high velocities, while others argue that they populate a similar range of environments as the normal-size massive galaxies, suggesting that there has to be another channel leading their survivor in low-dense environments. In my talk, I will discuss if red nuggets at intermediate redshift prefer a dense environment as the theory and first observations suggest or if they are found in low-dense environments.